Help with iMac display issue

[Makaveli6103]

This is a friends 2009 iMac. I have searched around and cannot figure out what it is. Aside form the squares the computer freezes every once and a while also. Reset PRAM, VRAM and ran the Apple Hardware test with nothing

 

[rkaufmann87]

This is a friends 2009 iMac. I have searched around and cannot figure out what it is. Aside form the squares the computer freezes every once and a while also. Reset PRAM, VRAM and ran the Apple Hardware test with nothing

Did you run AHT in Extended Mode at least 3x back to back, if not you really didn't run AHT. It's not the most reliable test but it's what you have available, if you don't run as described you're just wasting time.